Is there an Excel formula that can do the regression to find the best
quadratic fit for a set of x-y data.

The equation would be
y = a0 + a1 * x + a2 * x^2

I know that index(linest(...),..) can give me individual coefficients
for a simpler linear equation y = a0 + a1 * x.
Is there a similar formula for the equation above? I don't want to
go through multiple menus or create extra 'dummy' columns.
Any simpler way? Thanks.

Kaspa